The present invention relates to the cleaning and/or enlargement, or shaping, of passages in bodies made of a variety of materials. The invention is particularly applicable, but not limited, to passages in mineral or organic structures encountered in the fields of dentistry and medicine.
The state of the art with respect to dental applications will be discussed, solely by way of example.
The second step in the usual endodontic procedure involves cleaning and widening of the tooth canal. Cleaning involves removal of soft tissue, i.e., pulp and nerve tissue, while widening or enlargement of the canal requires removal of dentin material forming the canal wall. Conventionally, these operations are performed with the aid of a series of files having progressively increasing diameters and working in a moist medium. This work is performed most commonly by manual operation of the files and while introducing and irrigating fluid into the canal with the aid of a syringe. Such techniques are demanding inasmuch as they require very precise longitudinal movements, causing the practitioner to experience fatigue, which is physical as well as in the form of stress, since it is virtually impossible to control the action of such a file in a perfect manner.
Recently, automated techniques have made possible simultaneous cleaning and enlargement of tooth canals, with the aid of sonic or ultrasonic energy which, by vibrating a dental file, permits: enlargement due to high frequency movements induced in the file; and cleaning due to turbulence created in the irrigating fluid contained in the canal.
These automated techniques, however, have their own inherent drawbacks in that, for example, the vibrations induced in the files are on occasion disagreeable or poorly controlled by the practitioner. In particular, these vibrations require a very precise control during manipulation, which renders the use of these techniques very demanding.